Circuit-controller.



H. P. REED. CIRCUIT-CONTROLLER.

APPLICATIO! FILE. IUNE13. 1913.

Patented Mar. 14, 1916.

UNITED STATES PATENT onrron HARRISON P. REED, OF MILWAUKEE, WISCONSIN, ASSIGNOB TO THE CUTLER-HAMMER MFG. 00., OF MILWAUKEE, WISCONSIN, A. CORPORATION OF WISCONSIN.

CIRCUIT-CONTROLLER.

Specification of Letters Patent.

Patented Mar. 14, 1916.

Application filed June 13, 1913. Serial No. 773,400.

To all whom it mag concern:

Be it known that I, HARRISON P. REED, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of lVisconsin, have invented new and useful Improvements in Circuit-Controllers, of which the following is a full, clear, concise, and exact'description, reference being had to the accompanying drawing, forming a art of this specification.

y invention relates to improvements in circuit controllers particularly adapted to electric motors.

It has among its objects to provide a controller having electro-responsive tripping means with improved means for automatically rendering said former means ineffective under certain conditions.

A further object is to provide a motor controller having overload tripping means, with means for rendering said tripping means temporarily ineffective during the startin period of the motor.

A still further object is to provide a controller of the aforesaid type which will be particularly applicable to alternating current motors.

Other objects and advantages of my invention will hereinafter appear.

For the purpose of clearly and fully disclosing my invention I shall describe the embodiment thereof diagrammatically illustrated in the accompanying drawing, it bein understood that my invention is susceptible of modification. I

The controller illustrated is particularly applicable to alternating current motors and is illustrated as applied to such use. I have shown the controller as applied to a threephase alternating current motor 1, but of course it should be understood that the type of motor might be varied as desired. The controller includes an electro-responsive main switch 2 controlling the continuity of the primary circuit of the motor, overload switches 3 and 4: and a relay switch 5. As will be hereinafter more fully set forth, the overload switches upon responding function to denergize the main switch 2 to disconnect the motor from circuit, while the relay 5 functions to effect the closure of the switch 2 and to render the overload switches unresponsive for a definite period thereafter.

The main switch 2 is illustrated as of the double-pole type having poles 6 and 7 which control the continuity of the circuit to two termlnals of the motor, the third terminal of the motor being directly connected to the supplyline. In addition, the switch 2 is provided with two auxiliary switches 8 and 9 insulated therefrom and operated thereby. I he auxillary switch 8 is normally open and 1s closed upon closure of switch 2. The auxlhary switch 9 on the other hand is normally closed and is opened upon closure of switch 2. The overload switches 3 and 4: are shown as of a conventional type, the same comprising normally closed switches adapted to be opened upon response of their respective windings. Both overload switches are connected in series with the operating winding of main switch 2. Accordingly, response of either overload switch deenergizes the switch 2. Of course, the overload devices might assume various other forms, as for example, fuses.

The relay switch 5, as illustrated, is provided with three sets of contacts 10, 11 and 12, all of which are normally open. All

three of these sets of contacts are adapted to be closed by energization of a solenoid 13 through the solenoid lunger 14 and suitable connections 15. 1 dash-pot 16 is provided to retard the descent of the plunger 14, thereby retarding the opening of the relay contacts for a definite time following the deenergization of the relay. The contacts 12 when closed complete the energizing circuit of main switch 2 while the contacts 10 and 11 when closed respectively shortcircuit the operating windings of overload switches 3 and 4.

A control switch 17 is illustrated for controlling the relay and main switch, as hereinafter" set forth, and a triple-pole knife switch 18 is provided for establishing connections with a three-phase supply chcuit illustrated, as provided with lines 19, 20 and 21. Also, fuses 22 and 23 are illustrated for protection of" the control circuits, as will hereinafter clearly appear.

I shall now more fully describe the operation and functions of the controller by tracing the circuits illustrated. Assume that" the control switch 17 is closed. This conipletes a circuit from line 19 through lmife switch 18, by conductor 24 through fuse 22, by conductor 25 through overload switches 4: and 3 in series, by conductor 26 through ilii switch 17, by conductors 27 and 28 through operating winding of relay 5, by conductor 29 through auxiliary switch 9 of main switch 2, by conductors 30, 31 and 32 through fuse 23, by conductors and 31 through knife switch 18 to line 20.. The relay thereupon responds. closing all three sets of contacts.

10,11 and 12 and energizing switch 2through the contacts 12. The energizing circuit of switch 2 may be traced, as already described, to conductor 27, thence by conductor 35 through the operating winding of said switch 2, by conductors 36 and 37 through relay contacts 12 to conductor 31 and thence to line 20 as already traced. The switchv 2 upon responding completes the motor circuit. The motor circuit may now be traced as followszOne circuit extends from line 19 through switch 18 by conductors 39 and 40 through relay contacts 10, thus short-circuiting the winding of overload switch 3, by

conductor 41 through pole G of switch 2, by

conductor 12, to the left hand terminal of the motor. A second circuit extends from line 20 through switch 18, by conductor 3f directly to the middle terminal of the motor. A third circuit extends from line 21 through switch 18 by conductors 43 and 44 through relay contacts 11, thereby short-circuiting the winding of overload switch 4, by conductor f5 through pole 7 of switch 2, by conductor $6 to the right hand terminal of the motor. Under such conditions the motor willxbe started with the overload windings short-circuited. This renders the overload switches ineffective and thereby allows the motor to take the desired amount of current for starting purposes, without undesirable tripping by the overload devices. However, the period of ineffectiveness of the overload switches is only temporary to facilitate the starting of the motor and after a definite interval the short-circuits around the overload windings are interrupted, thereby rendering the overload switches effective to protect the motor against overloads during continued operation thereof. It should of course be understood that any suitable means such as starting fuses may be employed to protect the motor against undue surges of current during the brief period that the over- 1 load coils are short-circuited. The removal of the short-circuits around the overload is accomplished in the following manner: \Vhen the switch 2 closes it opens the auxiliary switch 9, which thereupon deenergizes the relay 5. The plunger 14: of relay 5 then descends against the action of the dash-pot 16 and after a definite time interval opens 10 and 11. The winding ofoverload switch 3 is then connected in circuit between conductors 39 and .41, while the winding of overload switch 4 is connected between conductors 43 and 45. The overload switches are thereupon rendered responsive to overloads in any phase of the motor circuit. The relay 5 upon deenergization also opens the contacts 12, thereby interrupting the initial energizing circuit of main switch 2. Prior to this, however, the auxiliary switch 8 is closed, thereby establishing a maintaining circuit for said switch :2 from conductor 37, by conductor 17 through auxiliary switch 8 and thence to conductor 31.

What I claim as new and desire to secure by Letters Patent is:

1. In combination, a power operated circuit controller, an electro-responsive tripping device therefor and common means for effecting operation of said controller and electrically rendering said device inefiective for a limited period following the operation of said controller.

2. In combination, a power operated circuit controller, an electro-responsive tripping device therefor and common means for effecting operation of said controller and shunting the operating winding of said device for a limited period following the operation of said controller.

3. In combination, a power operated circuit controller, an electro-responsive tripping device therefor and means operable to effect the setting of said controller and thereafter automatically returning to initial position, said means electrically controlling said device to vary the sensitiveness thereof for a temporary period following the setting of said controller.

. 4. In combination, a power operated circuit controller, electro-responsive tripping means therefor and a device operable to effect the setting of said controller and to electrically vary the sensitiveness of said tripping means, said controller, when set, effecting a further operation of said device to render said tripping means independent thereof.

5. In combination, an electro-responsive circuit controller, electro-responsive tripping means therefor, a contact device operable to effect response of said controller and to shuntsaid tripping means to reduce the sensitiveness thereof, said controller upon responding effecting a further operation of said device to relieve said tripping means of said shunt and means for retarding said latter operation of said device.

6. In combination. an electro-responsive circuit controller, electro-responsive tripping means therefor and an electro-respon- 'sive device responsive to effect the setting of said controller and to electrically vary the sensitiveness of said tripping means, said device being deenergized upon response of said circuit controller and upon restoration to initial position restoring said tripping means to normal sensitiveness.

7. The combination with an overload circuit breaker having setting means controllable from a distant point, of means con-" trolling said former means and acting electrically on said circuit breaker to vary the sensitiveness thereof to overloads for a limited period after setting.

8. In combination, an overload circuitbreaker, and a relay for afiecting setting' thereof and electrically rendering the same independent of overloads and subsequently operating automatically to render said circuit-breaker subject to the action of overloads.

9. In combination, a

switch, an electro-responsive relay for affecting operation of said switch and deenergized by said switch when operated and an overload tripping device for said -'switch electrically rendered inefiective by said repower-operated switch, an electro-responsive relay for affecting operation of said swltch and denergized by said switch when operated and an overload tripping device for said switch electrically rendered ineffective by said relay until its return to a predetermined position and means for retarding the return operation of said relay when deenergized.

In Witness whereof, I have hereunto subscribed name in the presence of two Witnesses.

I HARRISON P. REED. "Witnesses: p

FRANK H. I'IUBBARD, TEKLA Basr 

